Process of producing aluminium nitrid.



y o SEHPEK. PROCESS OF PRODUCING ALUMINIUM NITRID.

APPLICATION FILED APR. I4. 19155 l ,2l l l @E Eatentedi Jan. 9, 1917.

.P STATES PATENT OFFICE.

orro'xa SERPEK, or PARIS, FRANCE, AssIeNoa To SOCIETE GN or PARIS,FRANCE.

PROCESS 0F PROD'UCIN G ALUMINIUM NITRID.

Specification of Letters Eatent.

Patented J an. 9, 1917.

Griginal application led October 23, 1913, Serial No. 796,918. Dividedand thisapplication led April 14,

1915. Serial No. 21,822.

To all whom it may concern.' f

Be it known that I, OTTOKAR SERPEK, a subject of the Emperor ofAustria-Hungary, and at present residing in Paris,

France, have invented an Improved Process of Producing Aluminium Nitrid, of which the following is a specification.

The invention relates toa process of obtaining aluminium nitrid in whicha mixture of carbon and aluminous material is heated in an atmospherecontaining nitrogen, this case being a division'of my application Ser.No. 796,913 iiled Oct. 23, 1913.

According to the invention, the reacting mixture is projected, either byfalling freely or under the iniiuence of a gaseous stream, through oneor more electric arcs in relatively narrow or restricted spaces whichare free from any solid obstacle and without the materials Ibeing ableto remain upon the walls of the furnace. For this reaction thetemperature of the heated zone, the length of this zone, and the speedof passage of the mixture through the latter, are evidently functionsone of another, in such a way that for example the higher thetemperature of the zone and the ,greater its length, the higher must beits speed. This temperature may attain or exceed the temperatures ofdecomposition of the aluminium nitrid obtained or of the primarysubstance first employed, because, by suitably regulating the speed withwhich the reacting substances are made to pass through the heated zone,it is possible to e'ect the desired reaction in a rapid manner withoutentailing decomposition of the aluminium nitrid obtained.

In order to raise to the suitable temperature the zone where thereaction takes place, therema-y be employed a tube in which one or morearcs may be produced. In this case, in order to distribute the heat moreuniformly, the arcs may be blown either magnetically or` by means of acurrent of gas which might consist of nitrogen for example in thepresent case. The solid bodies brought to the most suitable state(powder, grains, agglomerates, etc.) 'may fall vertically through theheated zone, the current of gas being then passed either in the same orin the opposite direction; again these bodies may be projected upward byusing a gaseous current suiiiciently strong to carry them. In this casethe apparatus in which the reaction takes place may also be horizontalor have any other direction.

In 'case the reaction were not completed after a single passage, thebodies intended to reactmight be passed successively through severalapparatus or several times through the same apparatus. The same might bedone with the gases. v 'I A s usual the heat contained in the gasesleaving the apparatus may be utilized for prelunlnary heating of thematerials to be treated and the heat contained in the solid materialsleaving the furnace Vbe used for heating the gases.

By way of example, I have indicated in a vertical sectional diagram anapparatus Which may be used in carrying out my process, but I do nothere claim this construction nor do I wish to conne myself thereto.

In this view, a indicates a vertical tube several meters high. It isinsulated externally as by walls of refractory and inert material C, E.Into this vertical tube will project one or more sets of electrodes Aand A1 to which conductors from a generator may be connected to producethe electric arc or arcs.

By means of a suitable .feeding device at G there is introduced at thetop of the tube a mixture of alumina or alumina-containing substancesand carbon in suitable proportions, and the mixture is allowed to flowfreely through the arcs, the particles being dispersed by fallingdownward by gravity in the presence of nitrogen introduced in# side thetube a, as by a pipe at D. In this instance the current of gas will flowdownward in the samer direction as the powdered RALE nns NITBURES,

material. In this way there is provided aluminium nitrid and this is soeven if the material attains a temperature of over Q300 C., which isthat of the decomposition of the nitrid. The rapidity of reaction is themore remarkable because the reaction of the formation of nitrid is not asimple absorption of nitrogen. The formation of nitrid is the result ofdouble reaction.

This process offers in comparison with all the processes at presentemployed for obtaining aluminium nitrid, among others the advantage ofnot involving rapid deterioration of the apparatus which at presentrenders some of these manufactures so costly.

I-claim as my invention: 1. A process of obtaining aluminium n1- trid,by heating aluminous material and carbon in an atmosphere contalningnitrogen, the solid bodies being projected freely through a space filledWith nitrogen and heated to the temperature of the reaction.

2. A process of obtaining aluminium nitrid, by heating aluminousmaterial and carbon in an atmosphere of nitrogen, the solid bodiesvbeingprojected in powdered form freely through a space filled With nitrogenand heated to the temperature of the reaction.

3. A process of obtaining. aluminium nitrid, by heating aluminousmaterial and carbon in an atmosphere of nitrogen, the solid bodies beingallowed to fall freely through a Space filled with nitrogen and heatedto the temperature of the reaction.

4. A process of obtaining aluminium niterial and carbon in inely dividedcond'i- `tion to be projected freely through an electric arc in thepresence of nitrogen.

5. A process of obtaining aluminium nitrid by causing a mixture ofaluminous material and carbon in finely divided condition to beprojected freely through an electric arc, together with a current ofnitrogen flowing in the same direction.

6. A process of obtaining aluminum nitrid, which consists in rapidlypassing carbon and aluminousmaterial in finely Vdivided conditionthrough. a zone heated to the reaction temperature in the presence ofnitrogen, the particles. being dispersed at the reaction zone to permitfree access of the heat and nitrogen thereto.

ln testimony whereof I have signed my name to this specification`OTTOKAR SERPEK.

